As solar cells, those using a photoelectric conversion device provided with a light absorption layer mainly comprised of a I-III-VI group compound semiconductor have been proposed (for example, Japanese Patent Application Laid-Open No. 2007-311578). The I-III-VI group compound semiconductor is a chalcopyrite-based compound semiconductor using CIGS or the like. The CIGS has a high light absorption coefficient, and is suitably applied so as to provide a thinner 15 photoelectric conversion device with a large area and reduce manufacturing costs thereof.
In the photoelectric conversion device, a plurality of photoelectric conversion cells are arranged side by side on a plane. In each of the photoelectric conversion cells, a lower electrode mainly comprised of a metal electrode or the like, a photoelectric conversion layer comprised of a semiconductor layer mainly including a light absorption layer, a buffer layer and the like, and an upper electrode mainly comprised of a transparent electrode, a metal electrode and the like are stacked on a substrate comprised of glass or the like, in this order. Moreover, the plural photoelectric conversion cells are electrically connected in series with one after another, with the upper electrode of one of adjacent photoelectric conversion cells being electrically connected to the lower electrode of the other photoelectric conversion cell by a connection conductor.